What year is the truck?
There are really only four different components in any blower system: control switches, relays, blower motors and blower motor resistors (well... and wiring). The only thing that is common to both front and rear fans (as far as I know) is the power feed circuit. Maybe the relay.
Nothing in the a/c system should affect the fan motors, so you either knocked off a plug somewhere or the power circuit is dead. In this case, a test light is your friend! Check for power at the motors, like 1-ton said. There might be a fusible link somewhere that popped, too.